<!DOCTYPE html> <!-- Any copyright is dedicated to the Public Domain. http://creativecommons.org/publicdomain/zero/1.0/ --> <html> <head> <title>CSS Test: Testing a horizontal flex container with box-sizing:border-box on its flex items</title> <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com"> <meta charset="utf-8"> <style> .container { display: flex; width: 100px; height: 30px; border: 1px solid black; float: left; margin: 2px; } .container > * { box-sizing: border-box; } .itemA { width: 30px; background: purple; border: 4px solid indigo; } .itemB { width: 50px; background: teal; border: 5px solid lightblue; } </style> </head> <body> <!-- FIRST ROW --> <!-- 1 inflexible item --> <div class="container"> <div class="itemA"></div> </div> <!-- 1 flexible item --> <div class="container"> <div class="itemA" style="flex-grow: 1"></div> </div> <div style="clear: both"></div> <!-- SECOND ROW --> <!-- 2 inflexible items --> <div class="container"> <div class="itemA"></div> <div class="itemB"></div> </div> <!-- 2 flexible items --> <div class="container"> <div class="itemA" style="flex-grow: 1"></div> <div class="itemB" style="flex-grow: 1"></div> </div> </body> </html>